\section[RnNames]{Extracting imported and top-level names in scope}
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module RnNames (
- rnImports, importsFromLocalDecls,
- rnExports,
- getLocalDeclBinders, extendRdrEnvRn,
- reportUnusedNames, finishDeprecations,
+ rnImports, getLocalNonValBinders,
+ rnExports, extendGlobalRdrEnvRn,
+ reportUnusedNames, finishWarnings,
) where
#include "HsVersions.h"
import DynFlags
-import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl,
- ForeignDecl(..), HsGroup(..), HsValBindsLR(..),
- Sig(..), collectHsBindLocatedBinders, tyClDeclNames,
- instDeclATs, isFamInstDecl,
- LIE )
+import HsSyn
+import TcEnv ( isBrackStage )
import RnEnv
import RnHsDoc ( rnHsDoc )
import IfaceEnv ( ifaceExportNames )
import Module
import Name
import NameEnv
-import UniqFM
import NameSet
-import OccName
import HscTypes
import RdrName
import Outputable
import SrcLoc
import FiniteMap
import ErrUtils
-import BasicTypes ( DeprecTxt, Fixity )
-import DriverPhases ( isHsBoot )
import Util
+import FastString
import ListSetOps
-import Data.List ( partition, concatMap, (\\), delete )
-import IO ( openFile, IOMode(..) )
-import Monad ( when, mplus )
+import Data.List ( partition, (\\), delete )
+import qualified Data.Set as Set
+import System.IO
+import Control.Monad
\end{code}
implicit_prelude <- doptM Opt_ImplicitPrelude
let prel_imports = mkPrelImports this_mod implicit_prelude imports
(source, ordinary) = partition is_source_import imports
- is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot
+ is_source_import (L _ (ImportDecl _ _ is_boot _ _ _)) = is_boot
ifOptM Opt_WarnImplicitPrelude (
when (notNull prel_imports) $ addWarn (implicitPreludeWarn)
| otherwise = [preludeImportDecl]
where
explicit_prelude_import
- = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- import_decls,
+ = notNull [ () | L _ (ImportDecl mod Nothing _ _ _ _) <- import_decls,
unLoc mod == pRELUDE_NAME ]
preludeImportDecl :: LImportDecl RdrName
preludeImportDecl
= L loc $
ImportDecl (L loc pRELUDE_NAME)
+ Nothing {- no specific package -}
False {- Not a boot interface -}
False {- Not qualified -}
Nothing {- No "as" -}
Nothing {- No import list -}
- loc = mkGeneralSrcSpan FSLIT("Implicit import declaration")
+ loc = mkGeneralSrcSpan (fsLit "Implicit import declaration")
rnImportDecl :: Module
-> LImportDecl RdrName
-> RnM (LImportDecl Name, GlobalRdrEnv, ImportAvails,AnyHpcUsage)
-rnImportDecl this_mod (L loc (ImportDecl loc_imp_mod_name want_boot
+rnImportDecl this_mod (L loc (ImportDecl loc_imp_mod_name mb_pkg want_boot
qual_only as_mod imp_details))
- =
- setSrcSpan loc $ do
+ = setSrcSpan loc $ do
+
+ when (isJust mb_pkg) $ do
+ pkg_imports <- doptM Opt_PackageImports
+ when (not pkg_imports) $ addErr packageImportErr
-- If there's an error in loadInterface, (e.g. interface
-- file not found) we get lots of spurious errors from 'filterImports'
let
imp_mod_name = unLoc loc_imp_mod_name
- doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
+ doc = ppr imp_mod_name <+> ptext (sLit "is directly imported")
- iface <- loadSrcInterface doc imp_mod_name want_boot
+ iface <- loadSrcInterface doc imp_mod_name want_boot mb_pkg
-- Compiler sanity check: if the import didn't say
-- {-# SOURCE #-} we should not get a hi-boot file
-- Issue a user warning for a redundant {- SOURCE -} import
-- NB that we arrange to read all the ordinary imports before
- -- any of the {- SOURCE -} imports
- warnIf (want_boot && not (mi_boot iface))
+ -- any of the {- SOURCE -} imports.
+ --
+ -- in --make and GHCi, the compilation manager checks for this,
+ -- and indeed we shouldn't do it here because the existence of
+ -- the non-boot module depends on the compilation order, which
+ -- is not deterministic. The hs-boot test can show this up.
+ dflags <- getDOpts
+ warnIf (want_boot && not (mi_boot iface) && isOneShot (ghcMode dflags))
(warnRedundantSourceImport imp_mod_name)
let
imp_mod = mi_module iface
- deprecs = mi_deprecs iface
+ warns = mi_warns iface
orph_iface = mi_orphan iface
has_finsts = mi_finsts iface
deps = mi_deps iface
-- True <=> import M ()
import_all = case imp_details of
Just (is_hiding, ls) -> not is_hiding && null ls
- other -> False
+ _ -> False
imports = ImportAvails {
- imp_mods = unitModuleEnv imp_mod (imp_mod, [(qual_mod_name, import_all, loc)]),
+ imp_mods = unitModuleEnv imp_mod [(qual_mod_name, import_all, loc)],
imp_orphs = orphans,
imp_finsts = finsts,
imp_dep_mods = mkModDeps dependent_mods,
}
-- Complain if we import a deprecated module
- ifOptM Opt_WarnDeprecations (
- case deprecs of
- DeprecAll txt -> addWarn (moduleDeprec imp_mod_name txt)
- other -> return ()
+ ifOptM Opt_WarnWarningsDeprecations (
+ case warns of
+ WarnAll txt -> addWarn (moduleWarn imp_mod_name txt)
+ _ -> return ()
)
- let new_imp_decl = L loc (ImportDecl loc_imp_mod_name want_boot
+ let new_imp_decl = L loc (ImportDecl loc_imp_mod_name mb_pkg want_boot
qual_only as_mod new_imp_details)
return (new_imp_decl, gbl_env, imports, mi_hpc iface)
)
+warnRedundantSourceImport :: ModuleName -> SDoc
warnRedundantSourceImport mod_name
- = ptext SLIT("Unnecessary {-# SOURCE #-} in the import of module")
+ = ptext (sLit "Unnecessary {-# SOURCE #-} in the import of module")
<+> quotes (ppr mod_name)
\end{code}
* the ImportAvails
created by its bindings.
-\begin{code}
--- Bool determines shadowing:
--- true: names in the group should shadow other UnQuals
--- with the same OccName (used in Template Haskell)
--- false: duplicates should be reported as an error
---
--- The UniqFM (OccName -> FixItem) associates a Name's OccName's
--- FastString with a fixity declaration (that needs the actual OccName
--- to be plugged in). This fixity must be brought into scope when such
--- a Name is.
-importsFromLocalDecls :: Bool -> HsGroup RdrName -> UniqFM (Located Fixity) -> RnM TcGblEnv
-importsFromLocalDecls shadowP group fixities
- = do { gbl_env <- getGblEnv
+Note [Top-level Names in Template Haskell decl quotes]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Consider a Template Haskell declaration quotation like this:
+ module M where
+ f x = h [d| f = 3 |]
+When renaming the declarations inside [d| ...|], we treat the
+top level binders specially in two ways
+
+1. We give them an Internal name, not (as usual) an External one.
+ Otherwise the NameCache gets confused by a second allocation of
+ M.f. (We used to invent a fake module ThFake to avoid this, but
+ that had other problems, notably in getting the correct answer for
+ nameIsLocalOrFrom in lookupFixity. So we now leave tcg_module
+ unaffected.)
+
+2. We make them *shadow* the outer bindings. If we don't do that,
+ we'll get a complaint when extending the GlobalRdrEnv, saying that
+ there are two bindings for 'f'.
+
+ This shadowing applies even if the binding for 'f' is in a
+ where-clause, and hence is in the *local* RdrEnv not the *global*
+ RdrEnv.
+
+We find out whether we are inside a [d| ... |] by testing the TH
+stage. This is a slight hack, because the stage field was really meant for
+the type checker, and here we are not interested in the fields of Brack,
+hence the error thunks in thRnBrack.
- ; avails <- getLocalDeclBinders gbl_env group
-
- ; (rdr_env', fix_env') <- extendRdrEnvRn shadowP (tcg_rdr_env gbl_env,
- tcg_fix_env gbl_env)
- avails fixities
-
- ; traceRn (text "local avails: " <> ppr avails)
-
- ; return (gbl_env { tcg_rdr_env = rdr_env',
- tcg_fix_env = fix_env'})
- }
+\begin{code}
+extendGlobalRdrEnvRn :: [AvailInfo]
+ -> MiniFixityEnv
+ -> RnM (TcGblEnv, TcLclEnv)
+ -- Updates both the GlobalRdrEnv and the FixityEnv
+ -- We return a new TcLclEnv only becuase we might have to
+ -- delete some bindings from it;
+ -- see Note [Top-level Names in Template Haskell decl quotes]
+
+extendGlobalRdrEnvRn avails new_fixities
+ = do { (gbl_env, lcl_env) <- getEnvs
+ ; stage <- getStage
+ ; let rdr_env = tcg_rdr_env gbl_env
+ fix_env = tcg_fix_env gbl_env
+
+ -- Delete new_occs from global and local envs
+ -- If we are in a TemplateHaskell decl bracket,
+ -- we are going to shadow them
+ -- See Note [Top-level Names in Template Haskell decl quotes]
+ shadowP = isBrackStage stage
+ new_occs = map (nameOccName . gre_name) gres
+ rdr_env1 = hideSomeUnquals rdr_env new_occs
+ lcl_env1 = lcl_env { tcl_rdr = delListFromOccEnv (tcl_rdr lcl_env) new_occs }
+ (rdr_env2, lcl_env2) | shadowP = (rdr_env1, lcl_env1)
+ | otherwise = (rdr_env, lcl_env)
+
+ rdr_env3 = foldl extendGlobalRdrEnv rdr_env2 gres
+ fix_env' = foldl extend_fix_env fix_env gres
+ (rdr_env', dups) = findLocalDupsRdrEnv rdr_env3 new_occs
+
+ gbl_env' = gbl_env { tcg_rdr_env = rdr_env', tcg_fix_env = fix_env' }
+
+ ; mapM_ addDupDeclErr dups
+
+ ; traceRn (text "extendGlobalRdrEnvRn" <+> (ppr new_fixities $$ ppr fix_env $$ ppr fix_env'))
+ ; return (gbl_env', lcl_env2) }
+ where
+ gres = gresFromAvails LocalDef avails
--- Bool determines shadowing as in importsFromLocalDecls.
--- UniqFM FixItem is the same as in importsFromLocalDecls.
---
--- Add the new locally-bound names one by one, checking for duplicates as
--- we do so. Remember that in Template Haskell the duplicates
--- might *already be* in the GlobalRdrEnv from higher up the module.
---
--- Also update the FixityEnv with the fixities for the names brought into scope.
---
--- Note that the return values are the extensions of the two inputs,
--- not the extras relative to them.
-extendRdrEnvRn :: Bool -> (GlobalRdrEnv, NameEnv FixItem)
- -> [AvailInfo] -> UniqFM (Located Fixity) -> RnM (GlobalRdrEnv, NameEnv FixItem)
-extendRdrEnvRn shadowP (rdr_env, fix_env) avails fixities =
- let -- if there is a fixity decl for the gre,
- -- add it to the fixity env
- extendFixEnv env gre =
- let name = gre_name gre
- occ = nameOccName name
- curKey = occNameFS occ in
- case lookupUFM fixities curKey of
- Nothing -> env
- Just (L _ fi) -> extendNameEnv env name (FixItem occ fi)
-
- (rdr_env_to_extend, extender) =
- if shadowP
- then -- when shadowing is on,
- -- (1) we need to remove the existing Unquals for the
- -- names we're extending the env with
- -- (2) but extending the env is simple
- let names = concatMap availNames avails
- new_occs = map nameOccName names
- trimmed_rdr_env = hideSomeUnquals rdr_env new_occs
- in
- (trimmed_rdr_env,
- \(cur_rdr_env, cur_fix_env) -> \gre ->
- return (extendGlobalRdrEnv cur_rdr_env gre,
- extendFixEnv cur_fix_env gre))
- else -- when shadowing is off,
- -- (1) we don't munge the incoming env
- -- (2) but we need to check for dups when extending
- (rdr_env,
- \(cur_rdr_env, cur_fix_env) -> \gre ->
- let gres = lookupGlobalRdrEnv cur_rdr_env (nameOccName (gre_name gre))
- in case filter isLocalGRE gres of -- Check for existing *local* defns
- dup_gre:_ -> do { addDupDeclErr (gre_name dup_gre) (gre_name gre)
- ; return (cur_rdr_env, cur_fix_env) }
- [] -> return (extendGlobalRdrEnv cur_rdr_env gre,
- extendFixEnv cur_fix_env gre))
- in foldlM extender (rdr_env_to_extend, fix_env) (gresFromAvails LocalDef avails)
+ -- If there is a fixity decl for the gre, add it to the fixity env
+ extend_fix_env fix_env gre
+ | Just (L _ fi) <- lookupFsEnv new_fixities (occNameFS occ)
+ = extendNameEnv fix_env name (FixItem occ fi)
+ | otherwise
+ = fix_env
+ where
+ name = gre_name gre
+ occ = nameOccName name
\end{code}
@getLocalDeclBinders@ returns the names for an @HsDecl@. It's
Instances of type families
~~~~~~~~~~~~~~~~~~~~~~~~~~
-Indexed data/newtype instances contain data constructors that we need to
-collect, too. Moreover, we need to descend into the data/newtypes instances
-of associated families.
+Family instances contain data constructors that we need to collect and we also
+need to descend into the type instances of associated families in class
+instances. The type constructor of a family instance is a usage occurence.
+Hence, we don't return it as a subname in 'AvailInfo'; otherwise, we would get
+a duplicate declaration error.
+
+Note [Looking up family names in family instances]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Consider
+
+ module M where
+ type family T a :: *
+ type instance M.T Int = Bool
+
+We might think that we can simply use 'lookupOccRn' when processing the type
+instance to look up 'M.T'. Alas, we can't! The type family declaration is in
+the *same* HsGroup as the type instance declaration. Hence, as we are
+currently collecting the binders declared in that HsGroup, these binders will
+not have been added to the global environment yet.
+
+In the case of type classes, this problem does not arise, as a class instance
+does not define any binders of it's own. So, we simply don't attempt to look
+up the class names of class instances in 'get_local_binders' below.
+
+If we don't look up class instances, can't we get away without looking up type
+instances, too? No, we can't. Data type instances define data constructors
+and we need to
+
+ (1) collect those in 'get_local_binders' and
+ (2) we need to get their parent name in 'get_local_binders', too, to
+ produce an appropriate 'AvailTC'.
-We need to be careful with the handling of the type constructor of each type
-instance as the family constructor is already defined, and we want to avoid
-raising a duplicate declaration error. So, we make a new name for it, but
-don't return it in the 'AvailInfo'.
+This parent name is exactly the family name of the type instance that is so
+difficult to look up.
+
+We solve this problem as follows:
+
+ (a) We process all type declarations other than type instances first.
+ (b) Then, we compute a 'GlobalRdrEnv' from the result of the first step.
+ (c) Finally, we process all type instances (both those on the toplevel and
+ those nested in class instances) and check for the family names in the
+ 'GlobalRdrEnv' produced in the previous step before using 'lookupOccRn'.
\begin{code}
--- Note: this function does NOT get the binders of the ValBinds that
--- will be bound during renaming
-getLocalDeclBinders :: TcGblEnv -> HsGroup RdrName -> RnM [AvailInfo]
-getLocalDeclBinders gbl_env (HsGroup {hs_valds = ValBindsIn val_decls val_sigs,
- hs_tyclds = tycl_decls,
- hs_instds = inst_decls,
- hs_fords = foreign_decls })
- = do { tc_names_s <- mapM new_tc tycl_decls
- ; at_names_s <- mapM inst_ats inst_decls
- ; val_names <- mapM new_simple val_bndrs
- ; return (val_names ++ tc_names_s ++ concat at_names_s) }
+getLocalNonValBinders :: HsGroup RdrName -> RnM [AvailInfo]
+-- Get all the top-level binders bound the group *except*
+-- for value bindings, which are treated separately
+-- Specificaly we return AvailInfo for
+-- type decls
+-- class decls
+-- associated types
+-- foreign imports
+-- (in hs-boot files) value signatures
+
+getLocalNonValBinders group
+ = do { gbl_env <- getGblEnv
+ ; get_local_binders gbl_env group }
+
+get_local_binders :: TcGblEnv -> HsGroup RdrName -> RnM [GenAvailInfo Name]
+get_local_binders gbl_env (HsGroup {hs_valds = ValBindsIn _ val_sigs,
+ hs_tyclds = tycl_decls,
+ hs_instds = inst_decls,
+ hs_fords = foreign_decls })
+ = do { -- separate out the family instance declarations
+ let (tyinst_decls1, tycl_decls_noinsts)
+ = partition (isFamInstDecl . unLoc) tycl_decls
+ tyinst_decls = tyinst_decls1 ++
+ concatMap (instDeclATs . unLoc) inst_decls
+
+ -- process all type/class decls except family instances
+ ; tc_names <- mapM new_tc tycl_decls_noinsts
+
+ -- create a temporary rdr env of the type binders
+ ; let tc_gres = gresFromAvails LocalDef tc_names
+ tc_name_env = foldl extendGlobalRdrEnv emptyGlobalRdrEnv tc_gres
+
+ -- process all family instances
+ ; ti_names <- mapM (new_ti tc_name_env) tyinst_decls
+
+ -- finish off with value binder in case of a hs-boot file
+ ; val_names <- mapM new_simple val_bndrs
+ ; return (val_names ++ tc_names ++ ti_names) }
where
mod = tcg_mod gbl_env
is_hs_boot = isHsBoot (tcg_src gbl_env) ;
+ for_hs_bndrs :: [Located RdrName]
for_hs_bndrs = [nm | L _ (ForeignImport nm _ _) <- foreign_decls]
-- In a hs-boot file, the value binders come from the
-- *signatures*, and there should be no foreign binders
+ val_bndrs :: [Located RdrName]
val_bndrs | is_hs_boot = [nm | L _ (TypeSig nm _) <- val_sigs]
| otherwise = for_hs_bndrs
+ new_simple :: Located RdrName -> RnM (GenAvailInfo Name)
new_simple rdr_name = do
nm <- newTopSrcBinder mod rdr_name
return (Avail nm)
- new_tc tc_decl
- | isFamInstDecl (unLoc tc_decl)
- = do { main_name <- lookupFamInstDeclBndr mod main_rdr
- ; sub_names <- mapM (newTopSrcBinder mod) sub_rdrs
- ; return (AvailTC main_name sub_names) }
- -- main_name is not bound here!
- | otherwise
+ new_tc tc_decl -- NOT for type/data instances
= do { main_name <- newTopSrcBinder mod main_rdr
; sub_names <- mapM (newTopSrcBinder mod) sub_rdrs
; return (AvailTC main_name (main_name : sub_names)) }
where
(main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl)
- inst_ats inst_decl
- = mapM new_tc (instDeclATs (unLoc inst_decl))
+ new_ti tc_name_env ti_decl -- ONLY for type/data instances
+ = do { main_name <- lookupFamInstDeclBndr tc_name_env main_rdr
+ ; sub_names <- mapM (newTopSrcBinder mod) sub_rdrs
+ ; return (AvailTC main_name sub_names) }
+ -- main_name is not bound here!
+ where
+ (main_rdr : sub_rdrs) = tyClDeclNames (unLoc ti_decl)
-getLocalDeclBinders _ _ = panic "getLocalDeclBinders" -- ValBindsOut can't happen
+get_local_binders _ g = pprPanic "get_local_binders" (ppr g)
\end{code}
-> [AvailInfo] -- What's available
-> RnM (Maybe (Bool, [LIE Name]), -- Import spec w/ Names
GlobalRdrEnv) -- Same again, but in GRE form
-
-filterImports iface decl_spec Nothing all_avails
+filterImports _ decl_spec Nothing all_avails
= return (Nothing, mkGlobalRdrEnv (gresFromAvails prov all_avails))
where
prov = Imported [ImpSpec { is_decl = decl_spec, is_item = ImpAll }]
(parent, subs) = if p1 == name then (p2, subs1) else (p1, subs2)
in
(name, AvailTC name subs, Just parent)
+ combine x y = pprPanic "filterImports/combine" (ppr x $$ ppr y)
lookup_lie :: Bool -> LIE RdrName -> TcRn [(LIE Name, AvailInfo)]
lookup_lie opt_typeFamilies (L loc ieRdr)
where
-- Warn when importing T(..) if T was exported abstractly
checkDodgyImport stuff
- | IEThingAll n <- ieRdr, (_, AvailTC _ [one]):_ <- stuff
+ | IEThingAll n <- ieRdr, (_, AvailTC _ [_]):_ <- stuff
= ifOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn n))
-- NB. use the RdrName for reporting the warning
checkDodgyImport _
return [mkIEThingAbs nameAvail]
IEThingWith tc ns -> do
- (name, AvailTC name2 subnames, mb_parent) <- lookup_name tc
+ (name, AvailTC _ subnames, mb_parent) <- lookup_name tc
let
env = mkOccEnv [(nameOccName s, s) | s <- subnames]
mb_children = map (lookupOccEnv env . rdrNameOcc) ns
where
mkIEThingAbs (n, av, Nothing ) = (IEThingAbs n, trimAvail av n)
- mkIEThingAbs (n, av, Just parent) = (IEThingAbs n, AvailTC parent [n])
+ mkIEThingAbs (n, _, Just parent) = (IEThingAbs n, AvailTC parent [n])
catMaybeErr :: [MaybeErr err a] -> [a]
mkUnitAvail me NoParent | isTyConName me = AvailTC me [me]
| otherwise = Avail me
-plusAvail (Avail n1) (Avail n2) = Avail n1
-plusAvail (AvailTC n1 ns1) (AvailTC n2 ns2) = AvailTC n2 (ns1 `unionLists` ns2)
+plusAvail :: GenAvailInfo Name -> GenAvailInfo Name -> GenAvailInfo Name
+plusAvail (Avail n1) (Avail _) = Avail n1
+plusAvail (AvailTC _ ns1) (AvailTC n2 ns2) = AvailTC n2 (ns1 `unionLists` ns2)
plusAvail a1 a2 = pprPanic "RnEnv.plusAvail" (hsep [ppr a1,ppr a2])
availParent :: Name -> AvailInfo -> Parent
-availParent n (Avail _) = NoParent
-availParent n (AvailTC m ms) | n==m = NoParent
- | otherwise = ParentIs m
+availParent _ (Avail _) = NoParent
+availParent n (AvailTC m _) | n == m = NoParent
+ | otherwise = ParentIs m
trimAvail :: AvailInfo -> Name -> AvailInfo
-trimAvail (Avail n) m = Avail n
+trimAvail (Avail n) _ = Avail n
trimAvail (AvailTC n ns) m = ASSERT( m `elem` ns) AvailTC n [m]
-- | filters 'AvailInfo's by the given predicate
let left = filter keep ns in
if null left then rest else AvailTC tc left : rest
--- | Given an import/export spec, construct the appropriate 'GlobalRdrElt's.
+-- | Given an import\/export spec, construct the appropriate 'GlobalRdrElt's.
gresFromIE :: ImpDeclSpec -> (LIE Name, AvailInfo) -> [GlobalRdrElt]
gresFromIE decl_spec (L loc ie, avail)
= gresFromAvail prov_fn avail
where
is_explicit = case ie of
- IEThingAll name -> \n -> n==name
- other -> \n -> True
+ IEThingAll name -> \n -> n == name
+ _ -> \_ -> True
prov_fn name = Imported [imp_spec]
where
imp_spec = ImpSpec { is_decl = decl_spec, is_item = item_spec }
mkChildEnv gres = foldr add emptyNameEnv gres
where
add (GRE { gre_name = n, gre_par = ParentIs p }) env = extendNameEnv_C (++) env p [n]
- add other_gre env = env
+ add _ env = env
findChildren :: NameEnv [Name] -> Name -> [Name]
findChildren env n = lookupNameEnv env n `orElse` []
emptyAvailEnv :: AvailEnv
emptyAvailEnv = emptyNameEnv
+{- Dead code
unitAvailEnv :: AvailInfo -> AvailEnv
unitAvailEnv a = unitNameEnv (availName a) a
availEnvElts :: AvailEnv -> [AvailInfo]
availEnvElts = nameEnvElts
+-}
addAvail :: AvailEnv -> AvailInfo -> AvailEnv
addAvail avails avail = extendNameEnv_C plusAvail avails (availName avail) avail
[AvailInfo]) -- The accumulated exported stuff
-- Not nub'd!
+emptyExportAccum :: ExportAccum
emptyExportAccum = ([], emptyOccEnv, [])
type ExportOccMap = OccEnv (Name, IE RdrName)
tcg_dus = tcg_dus tcg_env `plusDU`
usesOnly (availsToNameSet final_avails) }) }
-
exports_from_avail :: Maybe [LIE RdrName]
-- Nothing => no explicit export list
-> GlobalRdrEnv
-> Module
-> RnM (Maybe [LIE Name], [AvailInfo])
-exports_from_avail Nothing rdr_env imports this_mod
+exports_from_avail Nothing rdr_env _imports _this_mod
= -- The same as (module M) where M is the current module name,
-- so that's how we handle it.
let
kids_env = mkChildEnv (globalRdrEnvElts rdr_env)
imported_modules = [ qual_name
- | (_, xs) <- moduleEnvElts $ imp_mods imports,
+ | xs <- moduleEnvElts $ imp_mods imports,
(qual_name, _, _) <- xs ]
exports_from_item :: ExportAccum -> LIE RdrName -> RnM ExportAccum
| otherwise
= do { implicit_prelude <- doptM Opt_ImplicitPrelude
- ; let { exportValid = (mod `elem` imported_modules)
+ ; warnDodgyExports <- doptM Opt_WarnDodgyExports
+ ; let { exportValid = (mod `elem` imported_modules)
|| (moduleName this_mod == mod)
- ; gres = filter (isModuleExported implicit_prelude mod)
- (globalRdrEnvElts rdr_env)
- }
+ ; gres = filter (isModuleExported implicit_prelude mod)
+ (globalRdrEnvElts rdr_env)
+ ; names = map gre_name gres
+ }
+
+ ; checkErr exportValid (moduleNotImported mod)
+ ; warnIf (warnDodgyExports && exportValid && null gres) (nullModuleExport mod)
- ; checkErr exportValid (moduleNotImported mod)
- ; warnIf (exportValid && null gres) (nullModuleExport mod)
+ ; addUsedRdrNames (concat [ [mkRdrQual mod occ, mkRdrUnqual occ]
+ | occ <- map nameOccName names ])
+ -- The qualified and unqualified version of all of
+ -- these names are, in effect, used by this export
- ; occs' <- check_occs ie occs (map gre_name gres)
+ ; occs' <- check_occs ie occs names
-- This check_occs not only finds conflicts
-- between this item and others, but also
-- internally within this item. That is, if
lookup_ie ie@(IEThingAll rdr)
= do name <- lookupGlobalOccRn rdr
let kids = findChildren kids_env name
- when (null kids)
- (if (isTyConName name) then addWarn (dodgyExportWarn name)
- -- This occurs when you export T(..), but
- -- only import T abstractly, or T is a synonym.
- else addErr (exportItemErr ie))
-
+ mkKidRdrName = case isQual_maybe rdr of
+ Nothing -> mkRdrUnqual
+ Just (modName, _) -> mkRdrQual modName
+ addUsedRdrNames $ map (mkKidRdrName . nameOccName) kids
+ warnDodgyExports <- doptM Opt_WarnDodgyExports
+ when (null kids) $
+ if isTyConName name
+ then when warnDodgyExports $ addWarn (dodgyExportWarn name)
+ else -- This occurs when you export T(..), but
+ -- only import T abstractly, or T is a synonym.
+ addErr (exportItemErr ie)
+
return (IEThingAll name, AvailTC name (name:kids))
lookup_ie ie@(IEThingWith rdr sub_rdrs)
(text "in export list"))
return (IEThingWith name names, AvailTC name (name:names))
- lookup_ie ie = panic "lookup_ie" -- Other cases covered earlier
+ lookup_ie _ = panic "lookup_ie" -- Other cases covered earlier
-------------
lookup_doc_ie :: IE RdrName -> RnM (IE Name)
lookup_doc_ie (IEDoc doc) = do rn_doc <- rnHsDoc doc
return (IEDoc rn_doc)
lookup_doc_ie (IEDocNamed str) = return (IEDocNamed str)
- lookup_doc_ie ie = panic "lookup_doc_ie" -- Other cases covered earlier
+ lookup_doc_ie _ = panic "lookup_doc_ie" -- Other cases covered earlier
+isDoc :: IE RdrName -> Bool
isDoc (IEDoc _) = True
isDoc (IEDocNamed _) = True
isDoc (IEGroup _ _) = True
-- They just clutter up the environment (esp tuples), and the parser
-- will generate Exact RdrNames for them, so the cluttered
-- envt is no use. To avoid doing this filter all the time,
- -- we use -fno-implicit-prelude as a clue that the filter is
+ -- we use -XNoImplicitPrelude as a clue that the filter is
-- worth while. Really, it's only useful for GHC.Base and GHC.Tuple.
--
-- It's worth doing because it makes the environment smaller for
-- every module that imports the Prelude
| otherwise
= case prov of
- LocalDef -> moduleName (nameModule name) == mod
+ LocalDef | Just name_mod <- nameModule_maybe name
+ -> moduleName name_mod == mod
+ | otherwise -> False
Imported is -> any unQualSpecOK is && any (qualSpecOK mod) is
-------------------------------
%*********************************************************
\begin{code}
-finishDeprecations :: DynFlags -> Maybe DeprecTxt
- -> TcGblEnv -> RnM TcGblEnv
--- (a) Report usasge of deprecated imports
--- (b) If the whole module is deprecated, update tcg_deprecs
--- All this happens only once per module
-finishDeprecations dflags mod_deprec tcg_env
+finishWarnings :: DynFlags -> Maybe WarningTxt
+ -> TcGblEnv -> RnM TcGblEnv
+-- (a) Report usage of imports that are deprecated or have other warnings
+-- (b) If the whole module is warned about or deprecated, update tcg_warns
+-- All this happens only once per module
+finishWarnings dflags mod_warn tcg_env
= do { (eps,hpt) <- getEpsAndHpt
- ; ifOptM Opt_WarnDeprecations $
+ ; ifOptM Opt_WarnWarningsDeprecations $
mapM_ (check hpt (eps_PIT eps)) all_gres
-- By this time, typechecking is complete,
-- so the PIT is fully populated
- -- Deal with a module deprecation; it overrides all existing deprecs
- ; let new_deprecs = case mod_deprec of
- Just txt -> DeprecAll txt
- Nothing -> tcg_deprecs tcg_env
- ; return (tcg_env { tcg_deprecs = new_deprecs }) }
+ -- Deal with a module deprecation; it overrides all existing warns
+ ; let new_warns = case mod_warn of
+ Just txt -> WarnAll txt
+ Nothing -> tcg_warns tcg_env
+ ; return (tcg_env { tcg_warns = new_warns }) }
where
used_names = allUses (tcg_dus tcg_env)
-- Report on all deprecated uses; hence allUses
| name `elemNameSet` used_names
, Just deprec_txt <- lookupImpDeprec dflags hpt pit gre
= addWarnAt (importSpecLoc imp_spec)
- (sep [ptext SLIT("Deprecated use of") <+>
+ (sep [ptext (sLit "In the use of") <+>
pprNonVarNameSpace (occNameSpace (nameOccName name)) <+>
quotes (ppr name),
(parens imp_msg) <> colon,
(ppr deprec_txt) ])
where
- name_mod = nameModule name
+ name_mod = ASSERT2( isExternalName name, ppr name ) nameModule name
imp_mod = importSpecModule imp_spec
- imp_msg = ptext SLIT("imported from") <+> ppr imp_mod <> extra
+ imp_msg = ptext (sLit "imported from") <+> ppr imp_mod <> extra
extra | imp_mod == moduleName name_mod = empty
- | otherwise = ptext SLIT(", but defined in") <+> ppr name_mod
+ | otherwise = ptext (sLit ", but defined in") <+> ppr name_mod
- check hpt pit ok_gre = return () -- Local, or not used, or not deprectated
+ check _ _ _ = return () -- Local, or not used, or not deprectated
-- The Imported pattern-match: don't deprecate locally defined names
-- For a start, we may be exporting a deprecated thing
-- Also we may use a deprecated thing in the defn of another
-- interface
lookupImpDeprec :: DynFlags -> HomePackageTable -> PackageIfaceTable
- -> GlobalRdrElt -> Maybe DeprecTxt
+ -> GlobalRdrElt -> Maybe WarningTxt
-- The name is definitely imported, so look in HPT, PIT
lookupImpDeprec dflags hpt pit gre
- = case lookupIfaceByModule dflags hpt pit (nameModule name) of
- Just iface -> mi_dep_fn iface name `mplus` -- Bleat if the thing, *or
+ = case lookupIfaceByModule dflags hpt pit mod of
+ Just iface -> mi_warn_fn iface name `mplus` -- Bleat if the thing, *or
case gre_par gre of
- ParentIs p -> mi_dep_fn iface p -- its parent*, is deprec'd
+ ParentIs p -> mi_warn_fn iface p -- its parent*, is warn'd
NoParent -> Nothing
Nothing -> Nothing -- See Note [Used names with interface not loaded]
where
- name = gre_name gre
+ name = gre_name gre
+ mod = ASSERT2( isExternalName name, ppr name ) nameModule name
\end{code}
Note [Used names with interface not loaded]
its interface (although we could).
b) It might be GHC.Real.fromRational, or GHC.Num.fromInteger
- These are seen as "used" by the renamer (if -fno-implicit-prelude)
+ These are seen as "used" by the renamer (if -XNoImplicitPrelude)
is on), but the typechecker may discard their uses
if in fact the in-scope fromRational is GHC.Read.fromRational,
(see tcPat.tcOverloadedLit), and the typechecker sees that the type
\begin{code}
reportUnusedNames :: Maybe [LIE RdrName] -- Export list
-> TcGblEnv -> RnM ()
-reportUnusedNames export_decls gbl_env
+reportUnusedNames _export_decls gbl_env
= do { traceRn ((text "RUN") <+> (ppr (tcg_dus gbl_env)))
- ; warnUnusedTopBinds unused_locals
- ; warnUnusedModules unused_imp_mods
- ; warnUnusedImports unused_imports
- ; warnDuplicateImports defined_and_used
- ; printMinimalImports minimal_imports }
+ ; warnUnusedImportDecls gbl_env
+ ; warnUnusedTopBinds unused_locals }
where
used_names :: NameSet
used_names = findUses (tcg_dus gbl_env) emptyNameSet
-- Note that defined_and_used, defined_but_not_used
-- are both [GRE]; that's why we need defined_and_used
-- rather than just used_names
- defined_and_used, defined_but_not_used :: [GlobalRdrElt]
- (defined_and_used, defined_but_not_used)
+ _defined_and_used, defined_but_not_used :: [GlobalRdrElt]
+ (_defined_and_used, defined_but_not_used)
= partition (gre_is_used used_names) defined_names
kids_env = mkChildEnv defined_names
unused_locals = filter is_unused_local defined_but_not_used
is_unused_local :: GlobalRdrElt -> Bool
is_unused_local gre = isLocalGRE gre && isExternalName (gre_name gre)
-
- unused_imports :: [GlobalRdrElt]
- unused_imports = mapCatMaybes unused_imp defined_but_not_used
- unused_imp :: GlobalRdrElt -> Maybe GlobalRdrElt -- Result has trimmed Imported provenances
- unused_imp gre@(GRE {gre_prov = LocalDef}) = Nothing
- unused_imp gre@(GRE {gre_prov = Imported imp_specs})
- | null trimmed_specs = Nothing
- | otherwise = Just (gre {gre_prov = Imported trimmed_specs})
- where
- trimmed_specs = filter report_if_unused imp_specs
-
- -- To figure out the minimal set of imports, start with the things
- -- that are in scope (i.e. in gbl_env). Then just combine them
- -- into a bunch of avails, so they are properly grouped
- --
- -- BUG WARNING: this does not deal properly with qualified imports!
- minimal_imports :: FiniteMap ModuleName AvailEnv
- minimal_imports0 = foldr add_expall emptyFM expall_mods
- minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
- minimal_imports = foldr add_inst_mod minimal_imports1 direct_import_mods
- -- The last line makes sure that we retain all direct imports
- -- even if we import nothing explicitly.
- -- It's not necessarily redundant to import such modules. Consider
- -- module This
- -- import M ()
- --
- -- The import M() is not *necessarily* redundant, even if
- -- we suck in no instance decls from M (e.g. it contains
- -- no instance decls, or This contains no code). It may be
- -- that we import M solely to ensure that M's orphan instance
- -- decls (or those in its imports) are visible to people who
- -- import This. Sigh.
- -- There's really no good way to detect this, so the error message
- -- in RnEnv.warnUnusedModules is weakened instead
-
- -- We've carefully preserved the provenance so that we can
- -- construct minimal imports that import the name by (one of)
- -- the same route(s) as the programmer originally did.
- add_name gre@(GRE {gre_prov = Imported (imp_spec:_)}) acc
- = addToFM_C plusAvailEnv acc
- (importSpecModule imp_spec) (unitAvailEnv (greAvail gre))
- add_name gre acc = acc -- Local
-
- -- Modules mentioned as 'module M' in the export list
- expall_mods = case export_decls of
- Nothing -> []
- Just es -> [m | L _ (IEModuleContents m) <- es]
-
- -- This is really bogus. The idea is that if we see 'module M' in
- -- the export list we must retain the import decls that drive it
- -- If we aren't careful we might see
- -- module A( module M ) where
- -- import M
- -- import N
- -- and suppose that N exports everything that M does. Then we
- -- must not drop the import of M even though N brings it all into
- -- scope.
- --
- -- BUG WARNING: 'module M' exports aside, what if M.x is mentioned?!
- --
- -- The reason that add_expall is bogus is that it doesn't take
- -- qualified imports into account. But it's an improvement.
- add_expall mod acc = addToFM_C plusAvailEnv acc mod emptyAvailEnv
+\end{code}
+
+%*********************************************************
+%* *
+ Unused imports
+%* *
+%*********************************************************
+
+This code finds which import declarations are unused. The
+specification and implementation notes are here:
+ http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/UnusedImports
+
+\begin{code}
+type ImportDeclUsage
+ = ( LImportDecl Name -- The import declaration
+ , [AvailInfo] -- What *is* used (normalised)
+ , [Name] ) -- What is imported but *not* used
+\end{code}
+
+\begin{code}
+warnUnusedImportDecls :: TcGblEnv -> RnM ()
+warnUnusedImportDecls gbl_env
+ = do { uses <- readMutVar (tcg_used_rdrnames gbl_env)
+ ; let imports = filter explicit_import (tcg_rn_imports gbl_env)
+ rdr_env = tcg_rdr_env gbl_env
- add_inst_mod (mod, _) acc
- | mod_name `elemFM` acc = acc -- We import something already
- | otherwise = addToFM acc mod_name emptyAvailEnv
+ ; let usage :: [ImportDeclUsage]
+ usage = findImportUsage imports rdr_env (Set.elems uses)
+
+ ; ifOptM Opt_WarnUnusedImports $
+ mapM_ warnUnusedImport usage
+
+ ; ifOptM Opt_D_dump_minimal_imports $
+ printMinimalImports usage }
+ where
+ explicit_import (L loc _) = isGoodSrcSpan loc
+ -- Filter out the implicit Prelude import
+ -- which we do not want to bleat about
+\end{code}
+
+\begin{code}
+findImportUsage :: [LImportDecl Name]
+ -> GlobalRdrEnv
+ -> [RdrName]
+ -> [ImportDeclUsage]
+
+type ImportMap = FiniteMap SrcLoc [AvailInfo]
+ -- The intermediate data struture records, for each import
+ -- declaration, what stuff brought into scope by that
+ -- declaration is actually used in the module.
+ --
+ -- The SrcLoc is the location of the start
+ -- of a particular 'import' declaration
+ --
+ -- The AvailInfos are the things imported from that decl
+ -- (just a list, not normalised)
+
+findImportUsage imports rdr_env rdrs
+ = map unused_decl imports
+ where
+ import_usage :: ImportMap
+ import_usage = foldr add_rdr emptyFM rdrs
+
+ unused_decl decl@(L loc (ImportDecl { ideclHiding = imps }))
+ = (decl, nubAvails used_avails, unused_imps)
where
- mod_name = moduleName mod
- -- Add an empty collection of imports for a module
- -- from which we have sucked only instance decls
-
- imports = tcg_imports gbl_env
-
- direct_import_mods :: [(Module, [(ModuleName, Bool, SrcSpan)])]
- -- See the type of the imp_mods for this triple
- direct_import_mods = moduleEnvElts (imp_mods imports)
-
- -- unused_imp_mods are the directly-imported modules
- -- that are not mentioned in minimal_imports1
- -- [Note: not 'minimal_imports', because that includes directly-imported
- -- modules even if we use nothing from them; see notes above]
- --
- -- BUG WARNING: this code is generally buggy
- unused_imp_mods :: [(ModuleName, SrcSpan)]
- unused_imp_mods = [(mod_name,loc)
- | (mod, xs) <- direct_import_mods,
- (_, no_imp, loc) <- xs,
- let mod_name = moduleName mod,
- not (mod_name `elemFM` minimal_imports1),
- mod /= pRELUDE,
- not no_imp]
- -- The not no_imp part is not to complain about
- -- import M (), which is an idiom for importing
- -- instance declarations
-
- module_unused :: ModuleName -> Bool
- module_unused mod = any (((==) mod) . fst) unused_imp_mods
-
- report_if_unused :: ImportSpec -> Bool
- -- Do we want to report this as an unused import?
- report_if_unused (ImpSpec {is_decl = d, is_item = i})
- = not (module_unused (is_mod d)) -- Not if we've already said entire import is unused
- && isExplicitItem i -- Only if the import was explicit
+ used_avails = lookupFM import_usage (srcSpanStart loc) `orElse` []
+ used_names = availsToNameSet used_avails
+
+ unused_imps = case imps of
+ Just (False, imp_ies) -> nameSetToList unused_imps
+ where
+ imp_names = mkNameSet (concatMap (ieNames . unLoc) imp_ies)
+ unused_imps = imp_names `minusNameSet` used_names
+
+ _other -> [] -- No explicit import list => no unused-name list
----------------------
-warnDuplicateImports :: [GlobalRdrElt] -> RnM ()
--- Given the GREs for names that are used, figure out which imports
--- could be omitted without changing the top-level environment.
---
--- NB: Given import Foo( T )
--- import qualified Foo
--- we do not report a duplicate import, even though Foo.T is brought
--- into scope by both, because there's nothing you can *omit* without
--- changing the top-level environment. So we complain only if it's
--- explicitly named in both imports or neither.
---
--- Furthermore, we complain about Foo.T only if
--- there is no complaint about (unqualified) T
-
-warnDuplicateImports gres
- = ifOptM Opt_WarnUnusedImports $
- sequence_ [ warn name pr
- | GRE { gre_name = name, gre_prov = Imported imps } <- gres
- , pr <- redundants imps ]
+ add_rdr :: RdrName -> ImportMap -> ImportMap
+ add_rdr rdr iu
+ = case lookupGRE_RdrName rdr rdr_env of
+ [gre] | Imported imps <- gre_prov gre
+ -> add_imp gre (bestImport imps) iu
+ _other -> iu
+
+ add_imp :: GlobalRdrElt -> ImportSpec -> ImportMap -> ImportMap
+ add_imp gre (ImpSpec { is_decl = imp_decl_spec }) iu
+ = addToFM_C add iu decl_loc [avail]
+ where
+ add avails _ = avail : avails
+ decl_loc = srcSpanStart (is_dloc imp_decl_spec)
+ name = gre_name gre
+ avail = case gre_par gre of
+ ParentIs p -> AvailTC p [p,name]
+ NoParent | isTyConName name -> AvailTC name [name]
+ | otherwise -> Avail name
+ -- If you use (+) from Num, then for this purpose we want
+ -- to say that Num is used as well. That is why in the
+ -- ParentIs case we have [p,name] in the ParentIs case
+
+bestImport :: [ImportSpec] -> ImportSpec
+bestImport iss
+ = case partition isImpAll iss of
+ ([], imp_somes) -> textuallyFirst imp_somes
+ (imp_alls, _) -> textuallyFirst imp_alls
+
+textuallyFirst :: [ImportSpec] -> ImportSpec
+textuallyFirst iss = case sortWith (is_dloc . is_decl) iss of
+ [] -> pprPanic "textuallyFirst" (ppr iss)
+ (is:_) -> is
+
+isImpAll :: ImportSpec -> Bool
+isImpAll (ImpSpec { is_item = ImpAll }) = True
+isImpAll _other = False
+\end{code}
+
+\begin{code}
+warnUnusedImport :: ImportDeclUsage -> RnM ()
+warnUnusedImport (L loc decl, used, unused)
+ | Just (False,[]) <- ideclHiding decl
+ = return () -- Do not warn for 'import M()'
+ | null used = addWarnAt loc msg1 -- Nothing used; drop entire decl
+ | null unused = return () -- Everything imported is used; nop
+ | otherwise = addWarnAt loc msg2 -- Some imports are unused
where
- warn name (red_imp, cov_imp)
- = addWarnAt (importSpecLoc red_imp)
- (vcat [ptext SLIT("Redundant import of:") <+> quotes pp_name,
- ptext SLIT("It is also") <+> ppr cov_imp])
- where
- pp_name | is_qual red_decl = ppr (is_as red_decl) <> dot <> ppr occ
- | otherwise = ppr occ
- occ = nameOccName name
- red_decl = is_decl red_imp
-
- redundants :: [ImportSpec] -> [(ImportSpec,ImportSpec)]
- -- The returned pair is (redundant-import, covering-import)
- redundants imps
- = [ (red_imp, cov_imp)
- | red_imp <- imps
- , isExplicitItem (is_item red_imp)
- -- Complain only about redundant imports
- -- mentioned explicitly by the user
- , cov_imp <- take 1 (filter (covers red_imp) imps) ]
- -- The 'take 1' picks the first offending group
- -- for this particular name
-
- -- "red_imp" is a putative redundant import
- -- "cov_imp" potentially covers it
- -- This test decides whether red_imp could be dropped
- --
- -- NOTE: currently the test does not warn about
- -- import M( x )
- -- imoprt N( x )
- -- even if the same underlying 'x' is involved, because dropping
- -- either import would change the qualified names in scope (M.x, N.x)
- -- But if the qualified names aren't used, the import is indeed redundant
- -- Sadly we don't know that. Oh well.
- covers red_imp@(ImpSpec { is_decl = red_decl, is_item = red_item })
- cov_imp@(ImpSpec { is_decl = cov_decl, is_item = cov_item })
- | red_loc == cov_loc
- = False -- Ignore diagonal elements
- | not (is_as red_decl == is_as cov_decl)
- = False -- They bring into scope different qualified names
- | not (is_qual red_decl) && is_qual cov_decl
- = False -- Covering one doesn't bring unqualified name into scope
- | otherwise
- = not (isExplicitItem cov_item) -- Redundant one is selective and covering one isn't
- || red_later -- or both are explicit; tie-break using red_later
-{-
- | red_selective
- = not cov_selective -- Redundant one is selective and covering one isn't
- || red_later -- Both are explicit; tie-break using red_later
- | otherwise
- = not cov_selective -- Neither import is selective
- && (is_mod red_decl == is_mod cov_decl) -- They import the same module
- && red_later -- Tie-break
--}
- where
- red_loc = importSpecLoc red_imp
- cov_loc = importSpecLoc cov_imp
- red_later = red_loc > cov_loc
-
--- ToDo: deal with original imports with 'qualified' and 'as M' clauses
-printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports
- -> RnM ()
-printMinimalImports imps
- = ifOptM Opt_D_dump_minimal_imports $ do {
-
- mod_ies <- initIfaceTcRn $ mapM to_ies (fmToList imps) ;
- this_mod <- getModule ;
- rdr_env <- getGlobalRdrEnv ;
- dflags <- getDOpts ;
- liftIO $ do h <- openFile (mkFilename this_mod) WriteMode
- printForUser h (mkPrintUnqualified dflags rdr_env)
- (vcat (map ppr_mod_ie mod_ies))
- }
+ msg1 = vcat [pp_herald <+> quotes pp_mod <+> pp_not_used,
+ nest 2 (ptext (sLit "except perhaps to import instances from")
+ <+> quotes pp_mod),
+ ptext (sLit "To import instances alone, use:")
+ <+> ptext (sLit "import") <+> pp_mod <> parens empty ]
+ msg2 = sep [pp_herald <+> quotes (pprWithCommas ppr unused),
+ text "from module" <+> quotes pp_mod <+> pp_not_used]
+ pp_herald = text "The import of"
+ pp_mod = ppr (unLoc (ideclName decl))
+ pp_not_used = text "is redundant"
+\end{code}
+
+To print the minimal imports we walk over the user-supplied import
+decls, and simply trim their import lists. NB that
+
+ * We do *not* change the 'qualified' or 'as' parts!
+
+ * We do not disard a decl altogether; we might need instances
+ from it. Instead we just trim to an empty import list
+
+\begin{code}
+printMinimalImports :: [ImportDeclUsage] -> RnM ()
+printMinimalImports imports_w_usage
+ = do { imports' <- mapM mk_minimal imports_w_usage
+ ; this_mod <- getModule
+ ; liftIO $
+ do { h <- openFile (mkFilename this_mod) WriteMode
+ ; printForUser h neverQualify (vcat (map ppr imports')) }
+ -- The neverQualify is important. We are printing Names
+ -- but they are in the context of an 'import' decl, and
+ -- we never qualify things inside there
+ -- E.g. import Blag( f, b )
+ -- not import Blag( Blag.f, Blag.g )!
+ }
where
mkFilename this_mod = moduleNameString (moduleName this_mod) ++ ".imports"
- ppr_mod_ie (mod_name, ies)
- | mod_name == moduleName pRELUDE
- = empty
- | null ies -- Nothing except instances comes from here
- = ptext SLIT("import") <+> ppr mod_name <> ptext SLIT("() -- Instances only")
- | otherwise
- = ptext SLIT("import") <+> ppr mod_name <>
- parens (fsep (punctuate comma (map ppr ies)))
- to_ies (mod, avail_env) = do ies <- mapM to_ie (availEnvElts avail_env)
- return (mod, ies)
+ mk_minimal (L l decl, used, unused)
+ | null unused
+ , Just (False, _) <- ideclHiding decl
+ = return (L l decl)
+ | otherwise
+ = do { ies <- initIfaceTcRn $ mapM to_ie used
+ ; return (L l (decl { ideclHiding = Just (False, map (L l) ies) })) }
to_ie :: AvailInfo -> IfG (IE Name)
-- The main trick here is that if we're importing all the constructors
where
all_used avail_occs = all (`elem` map nameOccName ns) avail_occs
doc = text "Compute minimal imports from" <+> ppr n
- n_mod = nameModule n
+ n_mod = ASSERT( isExternalName n ) nameModule n
\end{code}
-
%************************************************************************
%* *
\subsection{Errors}
%************************************************************************
\begin{code}
+badImportItemErr :: ModIface -> ImpDeclSpec -> IE RdrName -> SDoc
badImportItemErr iface decl_spec ie
- = sep [ptext SLIT("Module"), quotes (ppr (is_mod decl_spec)), source_import,
- ptext SLIT("does not export"), quotes (ppr ie)]
+ = sep [ptext (sLit "Module"), quotes (ppr (is_mod decl_spec)), source_import,
+ ptext (sLit "does not export"), quotes (ppr ie)]
where
- source_import | mi_boot iface = ptext SLIT("(hi-boot interface)")
+ source_import | mi_boot iface = ptext (sLit "(hi-boot interface)")
| otherwise = empty
-illegalImportItemErr = ptext SLIT("Illegal import item")
+illegalImportItemErr :: SDoc
+illegalImportItemErr = ptext (sLit "Illegal import item")
-dodgyImportWarn item = dodgyMsg (ptext SLIT("import")) item
-dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
+dodgyImportWarn :: RdrName -> SDoc
+dodgyImportWarn item = dodgyMsg (ptext (sLit "import")) item
+dodgyExportWarn :: Name -> SDoc
+dodgyExportWarn item = dodgyMsg (ptext (sLit "export")) item
+dodgyMsg :: OutputableBndr n => SDoc -> n -> SDoc
dodgyMsg kind tc
- = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr (IEThingAll tc)),
- ptext SLIT("suggests that") <+> quotes (ppr tc) <+> ptext SLIT("has constructors or class methods,"),
- ptext SLIT("but it has none") ]
-
+ = sep [ ptext (sLit "The") <+> kind <+> ptext (sLit "item") <+> quotes (ppr (IEThingAll tc))
+ <+> ptext (sLit "suggests that"),
+ quotes (ppr tc) <+> ptext (sLit "has (in-scope) constructors or class methods,"),
+ ptext (sLit "but it has none") ]
+
+exportItemErr :: IE RdrName -> SDoc
exportItemErr export_item
- = sep [ ptext SLIT("The export item") <+> quotes (ppr export_item),
- ptext SLIT("attempts to export constructors or class methods that are not visible here") ]
+ = sep [ ptext (sLit "The export item") <+> quotes (ppr export_item),
+ ptext (sLit "attempts to export constructors or class methods that are not visible here") ]
+typeItemErr :: Name -> SDoc -> SDoc
typeItemErr name wherestr
- = sep [ ptext SLIT("Using 'type' tag on") <+> quotes (ppr name) <+> wherestr,
- ptext SLIT("Use -XTypeFamilies to enable this extension") ]
+ = sep [ ptext (sLit "Using 'type' tag on") <+> quotes (ppr name) <+> wherestr,
+ ptext (sLit "Use -XTypeFamilies to enable this extension") ]
exportClashErr :: GlobalRdrEnv -> Name -> Name -> IE RdrName -> IE RdrName
-> Message
exportClashErr global_env name1 name2 ie1 ie2
- = vcat [ ptext SLIT("Conflicting exports for") <+> quotes (ppr occ) <> colon
+ = vcat [ ptext (sLit "Conflicting exports for") <+> quotes (ppr occ) <> colon
, ppr_export ie1' name1'
, ppr_export ie2' name2' ]
where
occ = nameOccName name1
- ppr_export ie name = nest 2 (quotes (ppr ie) <+> ptext SLIT("exports") <+>
+ ppr_export ie name = nest 2 (quotes (ppr ie) <+> ptext (sLit "exports") <+>
quotes (ppr name) <+> pprNameProvenance (get_gre name))
-- get_gre finds a GRE for the Name, so that we can show its provenance
then (name1, ie1, name2, ie2)
else (name2, ie2, name1, ie1)
-addDupDeclErr :: Name -> Name -> TcRn ()
-addDupDeclErr name_a name_b
- = addErrAt (srcLocSpan loc2) $
- vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr name1),
- ptext SLIT("Declared at:") <+> vcat [ppr (nameSrcLoc name1), ppr loc2]]
- where
- loc2 = nameSrcLoc name2
- (name1,name2) | nameSrcLoc name_a > nameSrcLoc name_b = (name_b,name_a)
- | otherwise = (name_a,name_b)
+addDupDeclErr :: [Name] -> TcRn ()
+addDupDeclErr []
+ = panic "addDupDeclErr: empty list"
+addDupDeclErr names@(name : _)
+ = addErrAt (getSrcSpan (last sorted_names)) $
-- Report the error at the later location
+ vcat [ptext (sLit "Multiple declarations of") <+> quotes (ppr name),
+ ptext (sLit "Declared at:") <+> vcat (map (ppr . nameSrcLoc) sorted_names)]
+ where
+ sorted_names = sortWith nameSrcLoc names
+dupExportWarn :: OccName -> IE RdrName -> IE RdrName -> SDoc
dupExportWarn occ_name ie1 ie2
= hsep [quotes (ppr occ_name),
- ptext SLIT("is exported by"), quotes (ppr ie1),
- ptext SLIT("and"), quotes (ppr ie2)]
+ ptext (sLit "is exported by"), quotes (ppr ie1),
+ ptext (sLit "and"), quotes (ppr ie2)]
+dupModuleExport :: ModuleName -> SDoc
dupModuleExport mod
- = hsep [ptext SLIT("Duplicate"),
- quotes (ptext SLIT("Module") <+> ppr mod),
- ptext SLIT("in export list")]
+ = hsep [ptext (sLit "Duplicate"),
+ quotes (ptext (sLit "Module") <+> ppr mod),
+ ptext (sLit "in export list")]
moduleNotImported :: ModuleName -> SDoc
moduleNotImported mod
- = ptext SLIT("The export item `module") <+> ppr mod <>
- ptext SLIT("' is not imported")
+ = ptext (sLit "The export item `module") <+> ppr mod <>
+ ptext (sLit "' is not imported")
+nullModuleExport :: ModuleName -> SDoc
nullModuleExport mod
- = ptext SLIT("The export item `module") <+> ppr mod <> ptext SLIT("' exports nothing")
-
-moduleDeprec mod txt
- = sep [ ptext SLIT("Module") <+> quotes (ppr mod) <+> ptext SLIT("is deprecated:"),
- nest 4 (ppr txt) ]
-
+ = ptext (sLit "The export item `module") <+> ppr mod <> ptext (sLit "' exports nothing")
+
+moduleWarn :: ModuleName -> WarningTxt -> SDoc
+moduleWarn mod (WarningTxt txt)
+ = sep [ ptext (sLit "Module") <+> quotes (ppr mod) <> ptext (sLit ":"),
+ nest 4 (ppr txt) ]
+moduleWarn mod (DeprecatedTxt txt)
+ = sep [ ptext (sLit "Module") <+> quotes (ppr mod)
+ <+> ptext (sLit "is deprecated:"),
+ nest 4 (ppr txt) ]
+
+implicitPreludeWarn :: SDoc
implicitPreludeWarn
- = ptext SLIT("Module `Prelude' implicitly imported")
+ = ptext (sLit "Module `Prelude' implicitly imported")
+
+packageImportErr :: SDoc
+packageImportErr
+ = ptext (sLit "Package-qualified imports are not enabled; use -XPackageImports")
\end{code}